A treatment tool for a hard endoscope is provided, on a bottom end thereof, with a slider which performs advancing and retracting operations of a distal operation section provided on a distal end side thereof. This slider has hole-shaped finger-receiving sections which are formed therein so as to be engageable with fingers during operations (for example, refer to FIG. 1 of Japanese Unexamined Patent Application, First Publication No. H08-131451).
On the other hand, a treatment tool for a flexible endoscope which is used by inserting it into a forceps channel of a flexible endoscope is provided with a finger-receiving member having sections which are engageable with fingers so as to operate this flexible endoscope.
As for this kind of treatment tools for an endoscope, one is proposed which is maintained in a manner such that an operation section stands on a forceps opening and does not descend; thereby, enabling stable operations by an operator of the endoscope (for example, refer to FIG. 1 of Japanese Utility Model, Publication No. H03-53211).
In the case in which the above-mentioned conventional treatment tool for an endoscope is operated by making it stand on the forceps opening, the finger-receiving section for a thumb is disposed on the upside, while the finger-receiving sections for a first finger and a second finger are disposed on the lower side. Therefore, finger arrangement will be opposite to an arrangement which is comfortable for a hand while holding an operation section. That is, as shown in the conventional treatment tool for an endoscope of FIG. 25, the operation section has to be gripped while bending the wrist during the operations.
In addition, there has been a conventional tool for an endoscope having a treatment tool distal end section which is operated by operating an operation section provided on the bottom end side, wherein: the operation section is provided on the bottom side of a sheath so as to be coaxial with the sheath; furthermore, a first finger engaging portion is provided on the bottom side of the operation section; and furthermore, a second finger engaging portion to which an operation wire is connected, is attached to a shaft body provided on the bottom side of the sheath so as to be advanceable and retractable (for example, refer to the Patent Publication No. 3,370,601). With this treatment tool for an endoscope, the operating section is held by engaging a thumb onto the first finger engaging portion and engaging other fingers onto the second finger engaging portion.
Furthermore, as for another example of the conventional operating section, there is one which is held by: engaging a thumb onto a ring connected to an operating wire; and sandwiching a grip provided on the bottom end side of a flexible operation duct section with the other fingers (for example, refer to FIG. 1 of Japanese Unexamined Patent Application, First Publication No. H02-224651).
When an operator of the endoscope operates the treatment tool for an endoscope using the above-mentioned operating section, as shown in the conventional treatment tool for an endoscope of FIG. 26, an operating section 119B will be held by turning the direction of a sheath 102B protruding from a forceps opening 123B of an endoscope 122B.